Ok, thanks!

-----Original Message-----
From: Christian König [mailto:[email protected]] 
Sent: Friday, July 21, 2017 10:12 PM
To: Yu, Xiangliang <[email protected]>; [email protected]
Subject: Re: [PATCH] drm/amdgpu: reduce the time of reading VBIOS

Am 21.07.2017 um 04:52 schrieb Xiangliang.Yu:
> From: Xiangliang Yu <[email protected]>
>
> Change ioremap mode from noncache to write combine and it will reduce 
> the read vbios time from 188ms to 8ms.

Nice improvement, but I think you need to improve the commit message a bit.

Changing the ioremap mode from noncache to write combine should actually not 
improve the read performance (reads are uncached in both modes).

I think this patch makes a difference because VRAM is usually marked write 
combined and so ioremap needs to change that for no good reason and that in 
turn takes quite some time.

I think you should write something like "Avoid changing the mapping mode of 
VRAM while reading the vbios from it, this reduce the time from....".

>
> Signed-off-by: Xiangliang Yu <[email protected]>
> Signed-off-by: Xiangliang.Yu <[email protected]>
You added the signed-off-by line twice, please fix this.

With that fixed and the commit message improved a bit the patch is
Reviewed-by: Christian König <[email protected]>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> index ea3a250..c21adf6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> @@ -104,7 +104,7 @@ static bool igp_read_bios_from_vram(struct 
> amdgpu_device *adev)
>   
>       adev->bios = NULL;
>       vram_base = pci_resource_start(adev->pdev, 0);
> -     bios = ioremap(vram_base, size);
> +     bios = ioremap_wc(vram_base, size);
>       if (!bios) {
>               return false;
>       }


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